Description this sim800L connects easily with arduino and other MCUs because of its inbuilt regulator. Features: 100% High Quality Model: SIM800L Work voltage: 3.7~5V Network support: Quad-Band 850 / 900/ 1800 / 1900 MHz – would work on GSM networks in all countries across the world. TTL serial interface compatible with 3.3V and 5V MCU Microcontrollers,competible with arduino .